When an image is captured by an imaging device such as a digital still camera and a digital video camera under illumination of low illuminance, in order to implement a more suitable imaging environment, auxiliary light is emitted toward a subject from a light source that is operated in linkage with the imaging device in some cases. In this manner, by emitting auxiliary light toward the subject, the imaging device can recognize the subject in the captured image, for example, even under illumination of low illuminance and can control a focal position according to an autofocus (AF) function and detect the subject according to a facial recognition technology and the like. For example, Patent Literature 1 discloses an example of a configuration in which auxiliary light is emitted toward a subject when an image is captured by an imaging device.